Motor-starting device



` Sept. 18, 1928.

E. C. BALLMAN MOTOR STARTING DEVICE Filed Nov.v 22. 1921 w va/ 0o 7 5 f\ Y R /o Y 5 L D @mi [mw/Y 6. ALL/VAN,

'Patented sept. 1s, 192s.

UNITED STATES PATENT OFFICE.

EDWIN ,C. BALLMAN, 0F ST. LOUIS, MISSOURI, ASSIGNOR TO VALLEY ELECTRIC COI- PANY, `0I' WILHINGTON, DELAWARE, A CORPORATION 0F DELAWARE.

l MOTOR-STARTING DEVICE.

Application'led November 22, 1921.

This invention relates to motor starting and protective devlces and is intended for use more particularly with so-called split.

` in that circuit out of phase with the current in the main winding so as `to provide the necessaryrevolving field for starting. When the motor is up to speed, the starting wind- `ing is opened and usually remains open during normal operation. The electro-motiveforce induced in the open starting winding during normal operation is substantially 20 proportional speed.

It is/one of the ob `ects of this invention, therefore, to utilize tlie changes of electromotive force in this starting winding to operate a protective device to open the motor 5 circuit under abnormal conditions.

Another object of this invention is to combine such a protective device with the starting device so that the same may be embodied in a compact and unitary structure.

Another object .of this invention is to provide a starting device 'which shall be simple to operate and which will operate the `motor against carelessness in handling and also against abnormal operating conditions.

Further objects willpappear from thedetail description taken in connectionwith the accompanying drawing which" illustrates diagrammatically the circuits and apparatus embodying this invention..

Referring to the accompanying drawing, 1 designates the motor armature, 2 the main field winding and 3 the starting winding. These are connected to the supply line 10 through the starting device. f'

The starting device comprises a switch 5 adapted` to connect the winding 2 to the supply line. This switch ymay be arranged lto stand normally open by means of a spring operated blade or other suitable device. The blade may be, provided with .a keeper 11 adapted for coo eration witha holding magnet 4 so that w en the switch is closed and the ma et energized, said magnet will hold the switch close The magnet 4 is provided with a wind- Serial` No. 517,024.

ing 6 which is connected across the terminals of the motor starting winding 3 so as to be energlzed by the electro-motive force induced 1n said starting winding. l

. The starting winding 3 is connected to the supply circuit through the usual resistance 7 and an auxiliary blade 8 coo erating with the starting switch 5. This b ade 8 is also spring-opened and is adapted when manipulated by means of the push-button handle 9 to make contact with the blade of the 4switch before said switch closes to -connect the main winding to the suppl line. Upon release 0f the handle 9, the b ade 8 will spring back so as to open the starting winding 3 even though the switch 5 may be held closed by the magnet 4. The handle 9 maybe provided with an extension 12 adapted to engage the switch 5 so that said switch may be opened manually by pulling on the handle 9. It is, of course, to be understood that the handle 9 represents a manipulative element which may be of any well known form including electrically operated manipulative levices which may be controlled from a disance.

The o eration of the device is as follows:

In starting a motor the manipulative element 9 is operated to first bring the switch blade 8 into contact with the blade of the switch 5 so as toconnect the main winding 2 andthe starting windin 3 togetherand then the switch 5 is close to connect both windings to the-supply line l0. The motor now starts in the well known manner. When the motor has reached full speed, the element 9 is released and the starting winding iso ened by thev spring action of the blade 8. he switch 5, however, will be held close'd by the magnet 4 lwhosewinding 6 is energized by the electro-motive force induced in the winding 3. The apparatus will be maintained in this condition so long as normal running conditions are maintained in the motor. When abnormal conditions .obtain as, for instance, when the motor is heavily overloaded, the speed thereof will drop and consequently the electro-motive force induced in the winding 3 will be reduced, thereby reducing the excitation of the magnet 4 to a point whereit will release the switch 5 to open the circuit and des motive :force across winding 3 will be correspondingly reduced and the ma et el will release the switch 5 to open the circuit. lt will be seen that this device provides both a starting device and a protective device for the motor as it is responsive to changes in the electrical conditions within the motor to protect the same against such conditions becoming abnormal and it is also responsive to changes in the supply line and will equally protect the motor against consequences thereof. Y

it is obvious that various changes may be made in details of construction without departing from the spirit oi this invention; it is, therefore, to be understood that this invention is not to be limite to the specific details shown and described.

Having thus described the invention, what is claimed is:

l. ln combination with an induction motor having main and starting windings, a switch adapted to connect said windings to a source oi' supply, and an electro-magnet connected in circuit with and controlled by current traversing the starting4 winding adapted to hold said switch to maintain con'.- nection with the source of supply.

2. ln combination with an induction motor having main and starting windings,

a switch adapted toconnect said windings to a source of supply, and an electro-magnet connected across said starting' winding and adapted to hold said switch to maintain connection with the source et supply,

8. lln combination with an electric motor having a main winding and an auxiliary windinc, a starting device, comprising, a double-bladed switch having one blade connected-tothe auxiliary winding and adapted for manipulation to contacting engagement with the other blade, and to move said other blade into contacting engagement with the supply circuit, means for holding said second blade in engagement with the sup lv circuit, and means for disengaging said rst blade..

4l. ln combination with an electric motor having a main'winding and a starting winding, a starting device, comprising, manipulative means for connecting' said windings together and to the line means adapted upon release of said manipulativel means to render said starting winding inactive, and magnetic means for holding said main winding closed,

5. ln combination with an electric motor having a main winding and an auxiliary winding, a starting device, comprising, manipulative means for connecting said windings together and to the line, mean adapted upon release of said manipulative means to open said auxiliary winding, and means connected to said auxiliary winding adapted to hold said main winding closed.

insane? 8. ln combination an electric motor having a main winding and an aaxillaryn winding., a starting device, comprising, manipulative means for connecting said windings together and to the line, means adapted upon release of said manipulative means to open said auxiliary winding', and means connected to and responsive to ,changes ol:a electro-motive torce in said'auxiliarv winding adapted to hold said main winding closed.

'.7. ln combination with an electric motor having a main winding and an auxiliary winding, a starting device, comprising, manipulative means for connecting said wind-y ings together and to the line, means adapted upon release of said manipulative means to open said auxiliary winding, and means connected to said auxiliarj,7 winding adapted to hold said main winding' closed and upon change in said auxiliary winding to open said main winding'.

8. lln combination with an electric .motor having a main winding and an auxiliary winding, a starting device, comprising manipulative means for connecting said windings together and to the line, means adapted upon relase ot said manipulative means to open said auxiliary winding, and means for holding said main winding closed adapted to open said main winding upon change of the motor speed.

9. ln combination with an electric motor having a main winding and an auniliary winding, a starting' device, comprising, a

double-bladed switch having one blade eonm@ l nected to the auxiliary winding, said blades being adapted for manipulation to contact1 engagement with the supply circuit, means for holding said second blade in ena gagement, and means for dieengaging said 3105 irst blade.

l0. xIn'combination withv an electric motor having a, main winding and an auxiliary winding, a starting' device, comprising, a `double-bladed switch having one blade conu@ nected the auxiliaifv winding and adapted for mampulation to contacting"l engagement with the other blade, said second'blade being connected the main winding` and adapted tor contactingr engagement with the supply mi circuit. means connected to one oi said windings i'or holding said second blade in engagereit, and means for disengaging said lirst ll.v lin combination with an electric motor 320 having a main winding and an auxiliary winding.. a starting device, comprising, av double-bladed switch having one blade connected to the auxiliary winding and 'adapted for manipulation to contacting engagement 25 with the other blade. said second blade being connected to the main winding' amd adapted for contacting engagement with'the supply circuit, means connected to said auxlliar;v windine for holding said second blade me u in engagement, and means for disengaging said first blade. 1-

w12. In combination with an electric motor having a main Winding and an auxiliary Winding, a starting device, comprising, aA

having a main winding and an auxiliary winding, a starting device, comprising, a

switch adapted to connect said windings together and thereafter to connect said windings to the supply line, and adapted to automatically open said auxiliary winding while said main Winding is held closed.

In testimony whereof I affix my signature this 28th day of April` 1921. EDWIN C. BALLMAN.' 

